We grow these each year and dig them up. We are in St. Louis. This year the foliage is absolutely gorgeous and healthy and lush, but the flowers are puny. I have noticed this on most throughout the area. Why would this be?
Certified GKH Gardening Expert
Canna Lily need full sun and warmth to bloom.
Make sure you are fertilizing with a balanced fertilizer such as 10-10-10 or 5-10-10. Too much nitrogen can cause lush greens but inhibit flowering.
If you fertilize your lawn and the Canna are planted in the ground, this can give them too much nitrogen.
Here is a link with more information.